CA1118847A - Surface smoothed tool joint hardfacing with grindable tie-in - Google Patents
Surface smoothed tool joint hardfacing with grindable tie-inInfo
- Publication number
- CA1118847A CA1118847A CA000331625A CA331625A CA1118847A CA 1118847 A CA1118847 A CA 1118847A CA 000331625 A CA000331625 A CA 000331625A CA 331625 A CA331625 A CA 331625A CA 1118847 A CA1118847 A CA 1118847A
- Authority
- CA
- Canada
- Prior art keywords
- tool joint
- granules
- arc
- band
- hardfacing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K31/00—Processes relevant to this subclass, specially adapted for particular articles or purposes, but not covered by only one of the preceding main groups
- B23K31/02—Processes relevant to this subclass, specially adapted for particular articles or purposes, but not covered by only one of the preceding main groups relating to soldering or welding
- B23K31/025—Connecting cutting edges or the like to tools; Attaching reinforcements to workpieces, e.g. wear-resisting zones to tableware
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K9/00—Arc welding or cutting
- B23K9/04—Welding for other purposes than joining, e.g. built-up welding
- B23K9/044—Built-up welding on three-dimensional surfaces
- B23K9/046—Built-up welding on three-dimensional surfaces on surfaces of revolution
- B23K9/048—Built-up welding on three-dimensional surfaces on surfaces of revolution on cylindrical surfaces
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
- C23C4/04—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the coating material
- C23C4/06—Metallic material
Abstract
ABSTRACT OF THE DISCLOSURE
An improved method for hardfacing tool joints for earth boring drill pipe. Annular bands of hardfacing are ap-plied by an apparatus that creates an arc between a consumable steel wire and the tool joint. The steel wire is reciprocated across the width of the band as the tool joint is rotated.
Granules of tungsten carbide flow by gravity from a hopper into the weld puddle. The flow of granules into the puddle is stopped just prior to reaching the tie-in point. The arc con-tinues a short distance, creating an overlapping protuberance at the tie in that is free of granules at the surface. This pro-tuberance can be easily ground smooth with the remainder of the hardfacing.
An improved method for hardfacing tool joints for earth boring drill pipe. Annular bands of hardfacing are ap-plied by an apparatus that creates an arc between a consumable steel wire and the tool joint. The steel wire is reciprocated across the width of the band as the tool joint is rotated.
Granules of tungsten carbide flow by gravity from a hopper into the weld puddle. The flow of granules into the puddle is stopped just prior to reaching the tie-in point. The arc con-tinues a short distance, creating an overlapping protuberance at the tie in that is free of granules at the surface. This pro-tuberance can be easily ground smooth with the remainder of the hardfacing.
Description
1~L18~3~7 BACKGROUND OF THE INVENTION
1. Field of the Invention . _ . . . _ This invention relates in general to earth boring drill pipe, and in particular to hardfacing the connection members on the drill pipe.
1. Field of the Invention . _ . . . _ This invention relates in general to earth boring drill pipe, and in particular to hardfacing the connection members on the drill pipe.
2. Description of the Prior Art The most common drill pipe used in earth boring operations have connection members or tool joints on each end that are larger in diametex than the drill pipe. Annular bands of hardfacing are commonly deposited on each tool joint. One type of hardfacing has macroscopic sintered tungsten carbide granules within an alloy steel matrix. Sintered tungsten car-bide granules, as explained in U.S. Patent 3,800,891, comprise microscopic grains of tungsten carbide held together by a binder of an iron group metal, usually cobalt. Sintered tungsten car-bide hardfacing is normally applied on tool joints by rotating the tool joint, providing an arc with a consumable steel wire, discharging an inert gas around the wire, and gravity feeding sintered tungsten carbide granules into the weld puddle behind ,the wire.
One disadvantage of the resulting sintered tungsten carbide hardfacing is that many of the granules remain only partially embedded in the matrix~ giving a rough~ abrasive exterior. In deep wells, intermediate strings of casing are set as the well is drilled. While drilling deeper through a string of intermediate casing, the rough surface of the hard-facing can abrade and damage the casing. Consequently, it is advantageous to have a hardfacing surface free of protruding tungsten carbide yranules. In U.S. patent No. 4,243,727 issued January 6,1981 entitled "SURFACE S~OOTHED TOOh JOINT
HARDFACING," a method and apparatus is shown for hard facing tool joints using
One disadvantage of the resulting sintered tungsten carbide hardfacing is that many of the granules remain only partially embedded in the matrix~ giving a rough~ abrasive exterior. In deep wells, intermediate strings of casing are set as the well is drilled. While drilling deeper through a string of intermediate casing, the rough surface of the hard-facing can abrade and damage the casing. Consequently, it is advantageous to have a hardfacing surface free of protruding tungsten carbide yranules. In U.S. patent No. 4,243,727 issued January 6,1981 entitled "SURFACE S~OOTHED TOOh JOINT
HARDFACING," a method and apparatus is shown for hard facing tool joints using
-3-, ~ .
i tungsten carbide granules that results in a smooth exterior.
The granules are dropped directly into the arc, rather than behincl the arc. This concen~rates the grallules toward the bottorn of the hardfacing deposit and results in a harder matrix near the bottom, as well.
One problem of this method occurs at the tie-in of the weld. The arc creates a generally circular pucldle.
It is oscillated less than the width of the groove or band to avoid overflow of hardfacing onto the other grooves. This re~
sults in a curved initiation point as seen in a side elevation-al view. To avoid a bare spo~, the initiation point is over-lapped slightly. This creates a slight protuberance at the tie-in~ During the overlapping, the granules continue to fall until the arc is stopped, and shortly thereafter. As a result~
granules fall into the puddle-as it cools, and become embedded in the surfaee of the deposit. It is desired to have a smooth surface hardfacing oE uniform thickness. Grinding this pro-tuberance is diffieult because of the granules embeclcled in the surface. For example, grinding of the protuberances of a typical tool joint may take l0 to lS minutes, while the hardEacing appli-eation may take only 6 to 8 m:inutes.
i tungsten carbide granules that results in a smooth exterior.
The granules are dropped directly into the arc, rather than behincl the arc. This concen~rates the grallules toward the bottorn of the hardfacing deposit and results in a harder matrix near the bottom, as well.
One problem of this method occurs at the tie-in of the weld. The arc creates a generally circular pucldle.
It is oscillated less than the width of the groove or band to avoid overflow of hardfacing onto the other grooves. This re~
sults in a curved initiation point as seen in a side elevation-al view. To avoid a bare spo~, the initiation point is over-lapped slightly. This creates a slight protuberance at the tie-in~ During the overlapping, the granules continue to fall until the arc is stopped, and shortly thereafter. As a result~
granules fall into the puddle-as it cools, and become embedded in the surfaee of the deposit. It is desired to have a smooth surface hardfacing oE uniform thickness. Grinding this pro-tuberance is diffieult because of the granules embeclcled in the surface. For example, grinding of the protuberances of a typical tool joint may take l0 to lS minutes, while the hardEacing appli-eation may take only 6 to 8 m:inutes.
-4-SU~ KY OF l`~lE INV NTION
It is accordingly a general object o~ ~his invention to provide an improve~ method of hardfacing a tool joint for ! earth boring drill pipe.
It is the further object of this invention to provide an improved method of hard~acing a tool joint for earth boring drill pipe in which the overlapped area at the ~ie-in is easily grindable.
It is the further object of this invention to provide an improved method of hardfacing a tool joi.nt for earth boring drill pipe in which the overlap at the tie-in is free of tungsten carbide granules at the surface.
In accordance with these objects, a new and useful hardfacing method is provided in which a timer controls the wheel conveyor that eeds the granules ~rom the hopper into the ~ 15 conduit that extends from the hopper to the weld puddle. I'he - timer is set to stop the conveyor wheel just before the arc reaches the initiation point. The arc continues on a short distance to create the protuberance at the overlap. This pro-tuberance, however, is ~ree of granules at the surace since the conveyor wheel ceased movernent ~rior to the ti.e-in point.
The lacl~ o~ granules at the surface allows the protuberance to be ea~ily ground.
According to a broad aspect of the invention, an imp.coved method is provided, for applying annular bands of hardfacing on a tool joint for earth boring drill pipe, the hardfacing having tungsten carbide granules in an alloy steel matrix, the method including the s~eps of rotating the tool joint, providing an arc between an electrode and the tool joint to create a weld puddle, reciprocating the electrode parallel to the tool joint a~is, and feeding the granules by gravity into the weld puddle, the improvic~ent comprising:
stopping the flow of granules into the puddle just before the band overlaps itself about the circumference of the tool joint after one revolution of the tool joint, but continuing the arc and tool joint reotation a selected distance to provide an overlapped protuberance of the band that is substantially free of granules at the surface, allowing the protuberance to be easily ground.
- 5a -BRIEI' DESCRIP'rION OF l'~lE Dl~AWINGS
... ... _ , Fig. 1 is a side elevational view of a portion of a tool joint construc~ed in accordance with th:is invention, ancl prior to grinding of the protuberances.
Fig. 2 is a sectional view of the tool joint of Fig. 1, taken along the line II-II.
Fig. 3 is a generally schematic end view of the apparatus for hardfacing the tool joint of Fig. 1.
Fig. 4 is a schematic diagram of a portion of the appara-tus of Yig. 3.
Fig. 5 is a side elevational view of a single band of the tool joint of Fig. 1, shown prior to completion and over-lapping of the band.
....... .
. .. . . .. . .
l~ t~
~ES~RI~'TION O~ PRLI~KRE.D EMBODII~NI' ~ eferring to Fig. l, a portion oE a tool joint 11 is shown with annular bancls 13 of hard~acing. As shown in Fig. 2, sintered tungsten carbide granules 15 are embedded in the matrix 17 of the hardfacing deposit. The surface 19 is smooth and is substantially f:ree o protruding granules 15. This hardfacing has been deposited by a hardfacing apparatus Zl, shown partially in Fig. 3.
Apparatus 21 includes means (not shown) for holding the too~ Joint 11 in a horizontal position and for rotating it in the direction shown by arrow 23. A guide member 25 is rnounted with its lower surface above the tool joint 11 approximately 3/4 lnch.
A consumable steel wire 27 is mounted on a driven roller 29 that feeds the wire through the center of guide member 25 toward the tool joint. The lower tip oE wire 27 is positioned approximately 1/8 inch from the surEace oE tool jo:int 11, leaving approxirnately
It is accordingly a general object o~ ~his invention to provide an improve~ method of hardfacing a tool joint for ! earth boring drill pipe.
It is the further object of this invention to provide an improved method of hard~acing a tool joint for earth boring drill pipe in which the overlapped area at the ~ie-in is easily grindable.
It is the further object of this invention to provide an improved method of hardfacing a tool joi.nt for earth boring drill pipe in which the overlap at the tie-in is free of tungsten carbide granules at the surface.
In accordance with these objects, a new and useful hardfacing method is provided in which a timer controls the wheel conveyor that eeds the granules ~rom the hopper into the ~ 15 conduit that extends from the hopper to the weld puddle. I'he - timer is set to stop the conveyor wheel just before the arc reaches the initiation point. The arc continues on a short distance to create the protuberance at the overlap. This pro-tuberance, however, is ~ree of granules at the surace since the conveyor wheel ceased movernent ~rior to the ti.e-in point.
The lacl~ o~ granules at the surface allows the protuberance to be ea~ily ground.
According to a broad aspect of the invention, an imp.coved method is provided, for applying annular bands of hardfacing on a tool joint for earth boring drill pipe, the hardfacing having tungsten carbide granules in an alloy steel matrix, the method including the s~eps of rotating the tool joint, providing an arc between an electrode and the tool joint to create a weld puddle, reciprocating the electrode parallel to the tool joint a~is, and feeding the granules by gravity into the weld puddle, the improvic~ent comprising:
stopping the flow of granules into the puddle just before the band overlaps itself about the circumference of the tool joint after one revolution of the tool joint, but continuing the arc and tool joint reotation a selected distance to provide an overlapped protuberance of the band that is substantially free of granules at the surface, allowing the protuberance to be easily ground.
- 5a -BRIEI' DESCRIP'rION OF l'~lE Dl~AWINGS
... ... _ , Fig. 1 is a side elevational view of a portion of a tool joint construc~ed in accordance with th:is invention, ancl prior to grinding of the protuberances.
Fig. 2 is a sectional view of the tool joint of Fig. 1, taken along the line II-II.
Fig. 3 is a generally schematic end view of the apparatus for hardfacing the tool joint of Fig. 1.
Fig. 4 is a schematic diagram of a portion of the appara-tus of Yig. 3.
Fig. 5 is a side elevational view of a single band of the tool joint of Fig. 1, shown prior to completion and over-lapping of the band.
....... .
. .. . . .. . .
l~ t~
~ES~RI~'TION O~ PRLI~KRE.D EMBODII~NI' ~ eferring to Fig. l, a portion oE a tool joint 11 is shown with annular bancls 13 of hard~acing. As shown in Fig. 2, sintered tungsten carbide granules 15 are embedded in the matrix 17 of the hardfacing deposit. The surface 19 is smooth and is substantially f:ree o protruding granules 15. This hardfacing has been deposited by a hardfacing apparatus Zl, shown partially in Fig. 3.
Apparatus 21 includes means (not shown) for holding the too~ Joint 11 in a horizontal position and for rotating it in the direction shown by arrow 23. A guide member 25 is rnounted with its lower surface above the tool joint 11 approximately 3/4 lnch.
A consumable steel wire 27 is mounted on a driven roller 29 that feeds the wire through the center of guide member 25 toward the tool joint. The lower tip oE wire 27 is positioned approximately 1/8 inch from the surEace oE tool jo:int 11, leaving approxirnately
5/8 inch of wire exposed. The longitudinal axis of ~he tool guide member 25 is inclined at an angle o~ approximately 23 degrees with respect to the vertical. Wire 27 serves as an electrode, and ~he point at which the arc is generated between wire 27 and the tool joint. surface is spaced Erom top dead center a circurll~erential distance equal to an angle o~ approximately 13 degrees with respect to the vertical. Top dead center is a point at which a vertical plan~ passes through the tool joint exterior sur~ace and the longitud:inal axis o~ the too:L joint.
~n inert gas, preEerably argon ~nd des.ignated as numeral 31, is discharged frolll guide rnember 25 and envelopes w:ire 27. Means ~no~ sllowil) are included :irl ttle apparatus to reciprocate the wi.re 27 acros.s the wi.dth oE the band 13, ~aral~el to the ].ongitudinaL axis of the tool As shown in Fi~. 3, granules of sintered tungsten carbicle 15 are gravity ~ecl from a conduit or a tube 33, which is at~ached ~o guide member 25 and inclined with respect to it.
Granules 15 are fecl tllrough an orifice 35 of tube 33 J then through an orifice 37 of an exkension block 39, and OIltO the surface of tool joint 11. Orifice 37 extends flush from orif:ice 33 at the same angle oE inclination. The forward edge of orifice 37 is positioned approximately 1/4 inch from wire 27.
The angle of inclination of orifice 37 is selected so that most of the ~ranules 15 will fall directly into the arc, as show.n iIl Fig. 3. In order to achieve the desired densities, orifices 35 : and 37 must be of certain cross-sectional areas, consequently, although concentrated, a certain amount of ~he particles will not fall directly into the arc, but will fall in close proxirnity to it.
~ hopper 41 for holding granules 15 is mounted above the tool joint 11. Hopper 41 has an outlet tube ~3 at its bottom.
A driven conveyor wheel 45 .is mounted adjacent the discharge end of the outlet tube 43. Wheel 45 has a plurality of recep-tacles 47 on its edge for conveying granules. ~leel 45 rotates by the end of the outlet tube ~3 for picking up the granules as ~:hey :~all out. Wheel 45 and hopp~r 41 are carried in a case ~9, The upper end o~ tube 33 terrninates at the bottom oE case 49 at a place where it recelves gran~lles conveyed by the wheel 45 as it rotates. A tray 51 surround.q the wheel 45, o~l~let 43, and entrance to tube 33 to receive granules that ovc~rflow receptacles ~7.
As shown in I~:i.g. 41 the apparatus ialcludes a motor for : rotatin~ wheel ~5. A weld ancl rolclLiorl ci.rcui.l: providt?c: l:he al C
and rotaLes the tool joi.nt. A cam 53 is mechallically driven bythe same apparatus that rotates the tool. jo:int. Cam 53 is drivtn by a sprocket (not ShOWII) with sli.~htly different num~er of teeth 111~8~7 than the drive sprocket (not shown) for the tool joint rotating mechanism. This causes it to rotate slightly faster than the tool joint. Cam 53 is adapted to actuate a limit switch 55 once each revolution. The rotational speed of cam 53 with respect to the tool joint rotation is selected so that it will complete its cycle and activate the limit switch 55 about 36 degrees before the arc starts its tie-in at the initiating point 57. Limit switch 55 si~nals two time delay relays, one of which allows the wheel 45 motor to revolve only a selected amount of time after the limit switch 55 is activated, the other of which allows the arc to continue only a selected ti~e interval after the limit switch 55 is activated. The arc time delay relay is slightly longer, typically about two seconds, than the wheel 45 motor time delay relay to avoid granules falling into the w~ccl puddle after the arc has started its tie-in at the arc initiating point.
In operation, granules of sintered tungsten carbide containing 5~/O to 7C~o cobalt are preferred, although other ranges and iron group binders are also feasible. One preferred size is minus 14 mesh to plus 30 mesh. To achieve a desired hardfacing density of .022 pounds per square inch, orifice 37 is approximately 1~8 inch wide and 1/8 inch high. Tool joint 11 is rotated at aproxi-mately one rotation per minute, which is about 20-22 circumfercntial inches per minute. The guide member is reciprocated 85 to 95 oscil-lations per minute along a 7/8 inch stroke. A slight overlap pro-vides bands of 3/4 inch width. An arc is struck to create a weld puddle, the temperatures generated being approximately 5000F.
Argon gas containing 5/O oxygen is pumped into the arc. ~eel 45 commences rotation substantially at the same time as the arc is created, dropping ~ranules of sintered tungsten carbide into t~e weld puddle at the arc. PreLerably 0.5 to 0.6 pounds per minute ~ 47 of sintered carbide granules are fed into the we'd puddle to achieve the desired density. The deposit averages 0.10 inch in thickness. Fig. 2 shows the appearance of the initia~ing point 57 prior to the tie-in, it being gradually curved at the S edges.
The hardfacing continues as the tool and cam 53 rotate.
The cam achieves a full revolution approximately when the tool joint has rotated about 324 degrees from initiating point 57. ~t this point cam 53 actuates limit switch 55, which in turn signals the wheel 45 motor time delay relay and the tirme delay relay for the arc. Slightly before the initiating poinTt 57, the wheel motor is stopped by its time delay relay, ceasing the flow of granules into the puddle. Approxirnately two seconds later, the arc is stopped by its time delay relay. This overlap of about 1/4 inch lS results in a protuberance 59, Fig. 2, that is substantially free of any granules at the surface. This protuberance can be easily ground snnooth within 1/32 inch o~ the remainder o~ the harclfaciTig band.
Grinding takes only approxima~ely one minute for the entire tool joint. v The resulting product has a surface free oE protruding granules. Some of the ~ranules are ernbedded near the surface, but substantially all of each granule is ~elow the ~urface. ~lost o~ the ~rantlles are concentrated ~owarc-l the ~ol:tom o~ the hard~acing deposit. The deposit contains ap~roximate:ly 50% sintered tun~sten carbidc granule.s and 50% matr:ix by weight.
'rhe wheel serves a~s valve rneans for allowing ancl per-; mitting the flow o grallules into the concluit. 'rhe whee] n~otor time clelay relay, cam, and limit swi~ch ~serve as nleans ~or auto-mal:iccllly actucltin~ the valve Tll~all.S to s~ol~ ~lle flow o~ g~J-allules 3~ into the welcl puddle.
.~ ... . ... . ,. _ .
The precise point at which the flow of granules ceases is not cri~ical, al~hough it is preferred to avold any portions that do not contain any granules. Preferably the polnt at which granules cease to flow ls witllin l/~ inch or so of the ln:itiating point. The cam and limit switch allow the operator to vary the speed of hardfaclng over most of the band while it is being applied to achieve the best results.
Varying the speed prior to actuation of the limit switch will not affect the time delay relays.
It should be apparent that an invention having sig-nificant advantages has been provided. The method provides smooth surface hardfacing for tool joints that can be ground at the tie-in to provide uniform thickness.
While the invention has been shown in only one of its forms, it should be apparent to those skilled in the art that it is not so limited but is susceptible to various changes and modifications without departing from the spirit thereof.
-1.1-
~n inert gas, preEerably argon ~nd des.ignated as numeral 31, is discharged frolll guide rnember 25 and envelopes w:ire 27. Means ~no~ sllowil) are included :irl ttle apparatus to reciprocate the wi.re 27 acros.s the wi.dth oE the band 13, ~aral~el to the ].ongitudinaL axis of the tool As shown in Fi~. 3, granules of sintered tungsten carbicle 15 are gravity ~ecl from a conduit or a tube 33, which is at~ached ~o guide member 25 and inclined with respect to it.
Granules 15 are fecl tllrough an orifice 35 of tube 33 J then through an orifice 37 of an exkension block 39, and OIltO the surface of tool joint 11. Orifice 37 extends flush from orif:ice 33 at the same angle oE inclination. The forward edge of orifice 37 is positioned approximately 1/4 inch from wire 27.
The angle of inclination of orifice 37 is selected so that most of the ~ranules 15 will fall directly into the arc, as show.n iIl Fig. 3. In order to achieve the desired densities, orifices 35 : and 37 must be of certain cross-sectional areas, consequently, although concentrated, a certain amount of ~he particles will not fall directly into the arc, but will fall in close proxirnity to it.
~ hopper 41 for holding granules 15 is mounted above the tool joint 11. Hopper 41 has an outlet tube ~3 at its bottom.
A driven conveyor wheel 45 .is mounted adjacent the discharge end of the outlet tube 43. Wheel 45 has a plurality of recep-tacles 47 on its edge for conveying granules. ~leel 45 rotates by the end of the outlet tube ~3 for picking up the granules as ~:hey :~all out. Wheel 45 and hopp~r 41 are carried in a case ~9, The upper end o~ tube 33 terrninates at the bottom oE case 49 at a place where it recelves gran~lles conveyed by the wheel 45 as it rotates. A tray 51 surround.q the wheel 45, o~l~let 43, and entrance to tube 33 to receive granules that ovc~rflow receptacles ~7.
As shown in I~:i.g. 41 the apparatus ialcludes a motor for : rotatin~ wheel ~5. A weld ancl rolclLiorl ci.rcui.l: providt?c: l:he al C
and rotaLes the tool joi.nt. A cam 53 is mechallically driven bythe same apparatus that rotates the tool. jo:int. Cam 53 is drivtn by a sprocket (not ShOWII) with sli.~htly different num~er of teeth 111~8~7 than the drive sprocket (not shown) for the tool joint rotating mechanism. This causes it to rotate slightly faster than the tool joint. Cam 53 is adapted to actuate a limit switch 55 once each revolution. The rotational speed of cam 53 with respect to the tool joint rotation is selected so that it will complete its cycle and activate the limit switch 55 about 36 degrees before the arc starts its tie-in at the initiating point 57. Limit switch 55 si~nals two time delay relays, one of which allows the wheel 45 motor to revolve only a selected amount of time after the limit switch 55 is activated, the other of which allows the arc to continue only a selected ti~e interval after the limit switch 55 is activated. The arc time delay relay is slightly longer, typically about two seconds, than the wheel 45 motor time delay relay to avoid granules falling into the w~ccl puddle after the arc has started its tie-in at the arc initiating point.
In operation, granules of sintered tungsten carbide containing 5~/O to 7C~o cobalt are preferred, although other ranges and iron group binders are also feasible. One preferred size is minus 14 mesh to plus 30 mesh. To achieve a desired hardfacing density of .022 pounds per square inch, orifice 37 is approximately 1~8 inch wide and 1/8 inch high. Tool joint 11 is rotated at aproxi-mately one rotation per minute, which is about 20-22 circumfercntial inches per minute. The guide member is reciprocated 85 to 95 oscil-lations per minute along a 7/8 inch stroke. A slight overlap pro-vides bands of 3/4 inch width. An arc is struck to create a weld puddle, the temperatures generated being approximately 5000F.
Argon gas containing 5/O oxygen is pumped into the arc. ~eel 45 commences rotation substantially at the same time as the arc is created, dropping ~ranules of sintered tungsten carbide into t~e weld puddle at the arc. PreLerably 0.5 to 0.6 pounds per minute ~ 47 of sintered carbide granules are fed into the we'd puddle to achieve the desired density. The deposit averages 0.10 inch in thickness. Fig. 2 shows the appearance of the initia~ing point 57 prior to the tie-in, it being gradually curved at the S edges.
The hardfacing continues as the tool and cam 53 rotate.
The cam achieves a full revolution approximately when the tool joint has rotated about 324 degrees from initiating point 57. ~t this point cam 53 actuates limit switch 55, which in turn signals the wheel 45 motor time delay relay and the tirme delay relay for the arc. Slightly before the initiating poinTt 57, the wheel motor is stopped by its time delay relay, ceasing the flow of granules into the puddle. Approxirnately two seconds later, the arc is stopped by its time delay relay. This overlap of about 1/4 inch lS results in a protuberance 59, Fig. 2, that is substantially free of any granules at the surface. This protuberance can be easily ground snnooth within 1/32 inch o~ the remainder o~ the harclfaciTig band.
Grinding takes only approxima~ely one minute for the entire tool joint. v The resulting product has a surface free oE protruding granules. Some of the ~ranules are ernbedded near the surface, but substantially all of each granule is ~elow the ~urface. ~lost o~ the ~rantlles are concentrated ~owarc-l the ~ol:tom o~ the hard~acing deposit. The deposit contains ap~roximate:ly 50% sintered tun~sten carbidc granule.s and 50% matr:ix by weight.
'rhe wheel serves a~s valve rneans for allowing ancl per-; mitting the flow o grallules into the concluit. 'rhe whee] n~otor time clelay relay, cam, and limit swi~ch ~serve as nleans ~or auto-mal:iccllly actucltin~ the valve Tll~all.S to s~ol~ ~lle flow o~ g~J-allules 3~ into the welcl puddle.
.~ ... . ... . ,. _ .
The precise point at which the flow of granules ceases is not cri~ical, al~hough it is preferred to avold any portions that do not contain any granules. Preferably the polnt at which granules cease to flow ls witllin l/~ inch or so of the ln:itiating point. The cam and limit switch allow the operator to vary the speed of hardfaclng over most of the band while it is being applied to achieve the best results.
Varying the speed prior to actuation of the limit switch will not affect the time delay relays.
It should be apparent that an invention having sig-nificant advantages has been provided. The method provides smooth surface hardfacing for tool joints that can be ground at the tie-in to provide uniform thickness.
While the invention has been shown in only one of its forms, it should be apparent to those skilled in the art that it is not so limited but is susceptible to various changes and modifications without departing from the spirit thereof.
-1.1-
Claims (4)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An improved method for applying annular bands of hard-facing on a tool joint for earth boring drill pipe, the hard-facing having tungsten carbide granules in an alloy steel matrix, the method including the steps of rotating the tool joint, providing an arc between an electrode and the tool joint to create a weld puddle, reciprocating the electrode parallel to the tool joint axis, and feeding the granules by gravity into the weld puddle, the improvement comprising:
stopping the flow of granules into the puddle just before the band overlaps itself about the circumference of the tool joint after one revolution of the tool joint, but con-tinuing the arc and tool joint rotation a selected distance to provide an overlapped protuberance of the band that is sub-stantially free of granules at the surface, allowing the pro-tuberance to be easily ground.
stopping the flow of granules into the puddle just before the band overlaps itself about the circumference of the tool joint after one revolution of the tool joint, but con-tinuing the arc and tool joint rotation a selected distance to provide an overlapped protuberance of the band that is sub-stantially free of granules at the surface, allowing the pro-tuberance to be easily ground.
2. An improved method for applying annular bands of hardfacing on a tool joint for earth boring drill pipe, the hardfacing having sintered tungsten carbide granules in an alloy steel matrix, the method including the steps of rotating the tool joint while providing an arc between a consumable steel wire and the tool joint within a stream of substantially inert gas to create a weld puddle, reciprocating the wire parallel to the tool joint axis, and feeding the granules by gravity into the weld puddle, the improvement comprising:
stopping the flow of granules just before the arc reaches its original initiating point on the circumference of the tool joint after one revolution of the tool joint, but continuing the arc a selected distance past the original initiating point to provide an overlapping protuberance of the band that is substantially free of granules at the surface, allowing the protuberance to be easily ground flush with the remainder of the band.
stopping the flow of granules just before the arc reaches its original initiating point on the circumference of the tool joint after one revolution of the tool joint, but continuing the arc a selected distance past the original initiating point to provide an overlapping protuberance of the band that is substantially free of granules at the surface, allowing the protuberance to be easily ground flush with the remainder of the band.
3. An improved method for applying annular bands of hard-facing on a tool joint for earth boring drill pipe, the hard-facing having sintered tungsten carbide granules in an alloy steel matrix, the method including the steps of rotating the tool joint while providing an arc between a consumable steel wire and the tool joint within a stream of substantially inert gas to create a weld puddle, reciprocating the wire parallel to the tool joint axis, and feeding the granules by gravity into the weld puddle, the improvement comprising:
initiating a timer means prior to reaching the initiating point at which the arc commenced for automatically stopping the flow of granules just before reaching the intiation point of the arc at the end of each hardfacing band, but continuing the arc and tool joint rotation a selected distance to provide an overlapping protuberance of the band at the initiating point that is substantially free of granules at the surface, allowing the protuberance to be easily ground flush with the remainder of the band.
initiating a timer means prior to reaching the initiating point at which the arc commenced for automatically stopping the flow of granules just before reaching the intiation point of the arc at the end of each hardfacing band, but continuing the arc and tool joint rotation a selected distance to provide an overlapping protuberance of the band at the initiating point that is substantially free of granules at the surface, allowing the protuberance to be easily ground flush with the remainder of the band.
4. An improved method for applying annular bands of hardfacing to a tool joint for earth boring drill pipe, comprising:
rotating the tool joint;
providing an arc between a consumable steel wire and the tool joint within a steam of substantially inert gas to create a weld puddle;
reciprocating the wire parallel with the tool joint axis substantially the width of the band;
mounting a hopper above the tool joint for holding granules of tungsten carbide, with an outlet at its bottom;
mounting a rotating wheel below the hopper outlet, the wheel having a receptacle for receiving granules and con-veying them over to a conduit that extends downwardly to a point near the tool joint;
rotating the wheel substantially at the initiation of the arc to cause granules to flow down the conduit into the weld puddle;
stopping the wheel immediately prior to reaching the point at which arc commenced after a band has been applied about the circumference of the tool joint, while the tool joint continues to rotate and the arc continues, to provide an overlapping band protuberance substantially free of granules to allow it to be easily ground.
rotating the tool joint;
providing an arc between a consumable steel wire and the tool joint within a steam of substantially inert gas to create a weld puddle;
reciprocating the wire parallel with the tool joint axis substantially the width of the band;
mounting a hopper above the tool joint for holding granules of tungsten carbide, with an outlet at its bottom;
mounting a rotating wheel below the hopper outlet, the wheel having a receptacle for receiving granules and con-veying them over to a conduit that extends downwardly to a point near the tool joint;
rotating the wheel substantially at the initiation of the arc to cause granules to flow down the conduit into the weld puddle;
stopping the wheel immediately prior to reaching the point at which arc commenced after a band has been applied about the circumference of the tool joint, while the tool joint continues to rotate and the arc continues, to provide an overlapping band protuberance substantially free of granules to allow it to be easily ground.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US05/974,168 US4228339A (en) | 1978-12-28 | 1978-12-28 | Method of hardfacing tool joints |
| US974,168 | 1978-12-28 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1118847A true CA1118847A (en) | 1982-02-23 |
Family
ID=25521685
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000331625A Expired CA1118847A (en) | 1978-12-28 | 1979-07-11 | Surface smoothed tool joint hardfacing with grindable tie-in |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US4228339A (en) |
| CA (1) | CA1118847A (en) |
Families Citing this family (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4414029A (en) * | 1981-05-20 | 1983-11-08 | Kennametal Inc. | Powder mixtures for wear resistant facings and products produced therefrom |
| US4666797A (en) * | 1981-05-20 | 1987-05-19 | Kennametal Inc. | Wear resistant facings for couplings |
| CH654030A5 (en) * | 1983-02-16 | 1986-01-31 | Castolin Sa | PROCESS FOR FORMING A WEAR RESISTANT COATING ON THE SURFACE OF A METAL SUBSTRATE. |
| US4625095A (en) * | 1983-03-08 | 1986-11-25 | The Boeing Company | Method of welding metal matrix composites |
| US5147996A (en) * | 1989-09-15 | 1992-09-15 | Grant Tfw, Inc. | Tool joint |
| US5010225A (en) * | 1989-09-15 | 1991-04-23 | Grant Tfw | Tool joint and method of hardfacing same |
| WO1997034026A1 (en) * | 1996-03-13 | 1997-09-18 | Cerma Shield (Proprietary) Limited | The coating of materials |
| AU737745B2 (en) * | 1997-06-19 | 2001-08-30 | Great Western Corporation Pty Ltd | An apparatus for hard facing |
| US8252225B2 (en) | 2009-03-04 | 2012-08-28 | Baker Hughes Incorporated | Methods of forming erosion-resistant composites, methods of using the same, and earth-boring tools utilizing the same in internal passageways |
| US7828089B2 (en) * | 2007-12-14 | 2010-11-09 | Baker Hughes Incorporated | Erosion resistant fluid passageways and flow tubes for earth-boring tools, methods of forming the same and earth-boring tools including the same |
| WO2010033742A2 (en) * | 2008-09-18 | 2010-03-25 | Baker Hughes Incorporated | Method and apparatus for the automated application of hardfacing material to rolling cutters of earth-boring bits |
| US9439277B2 (en) * | 2008-10-23 | 2016-09-06 | Baker Hughes Incorporated | Robotically applied hardfacing with pre-heat |
| US8450637B2 (en) * | 2008-10-23 | 2013-05-28 | Baker Hughes Incorporated | Apparatus for automated application of hardfacing material to drill bits |
| US8948917B2 (en) * | 2008-10-29 | 2015-02-03 | Baker Hughes Incorporated | Systems and methods for robotic welding of drill bits |
| EP2668362B1 (en) * | 2011-01-28 | 2020-01-01 | Baker Hughes, a GE company, LLC | Non-magnetic drill string member with non-magnetic hardfacing and method of making the same |
| US9289845B2 (en) | 2012-11-07 | 2016-03-22 | David S. Henn | Metal deposition of exterior members in oil field tubulars |
| EP3853435A4 (en) | 2018-09-21 | 2022-08-03 | Garland Industries, Inc. | Helical hardbanding |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2709213A (en) * | 1952-04-01 | 1955-05-24 | Air Reduction | Method of hard surfacing |
| US3405247A (en) * | 1964-12-03 | 1968-10-08 | Armco Steel Corp | Method and apparatus for producing smooth overlays for tool joints |
-
1978
- 1978-12-28 US US05/974,168 patent/US4228339A/en not_active Expired - Lifetime
-
1979
- 1979-07-11 CA CA000331625A patent/CA1118847A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| US4228339A (en) | 1980-10-14 |
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